[mustangparts65]

This has happened once before, although turning the truck off and then on has fixed the problem (in the past). The vent, or air, only blows through the defrost vents at the windshield- nothing comes out of the main dash vents- regardless of whether it is the AC, vent, floor, etc...

The vent worked great all day while driving around town but then it got a little warm out and it stopped working. I think I have seen this issue on the forum before- is it a vacuum leak, or some kind of valve or switch?

This is a 2000 F-350, diesel, XLT.

I tried turning the truck off a few times and it did not solve the problem today... What do I need to fix??

Thanks!

 

[gregrob]

Do you have the 4x4 switch in the dash? Most commonly it's a vacume leak caused by one of the lines going to the hubs coming off / breaking. Check those. It could also be the vacume pump itself going out.
Almost definitely a vacume issue.

 

[NCHornet]

Yes. It is a vacume leak. Check front hubs if 4x4 and follow the lines up to the vacume pump on the pass side fender. You will find either a cracked line or a bad pump, also look up under the dash in the pass foot well there is a line up there that can get kicked loose.

 

[upsman64]

mine did the same thing the other day,it was a fuse under the dash #22 i think.

 

[mustangparts65]

Sorry forgot to mention-

Truck is a 4x2...

If it is a bad vacuum pump, what else would stop working?

 

[mustangparts65]

All of the fuses are okay- I checked them.

 

[mustangparts65]

Checked the lines under the passenger foot well.. they are okay.

The lines are very soft so I doubt they are cracked.

Under the engine bay- is that little pump on the top of the passenger wheel well the vacuum pump? And is that the reservoir right next to it (the black oval thing)?

 

[NCHornet]

When you turn the key on you should hear the pump priming itself, do you? Could be a bad pump.

 

[MOUNTAINMAN444]

The only things I know the vacuum pump runs are: 4 wd hubs (which you don't have), air vent controller, and the turbo waste gate. If I'm wrong someone will help us out with the list. If you can get someone to turn on the switch for you you can place your hand on the pump and tell real easy whether it runs or not.
Joe

 

[444-4D]

[ QUOTE ]
and the turbo waste gate.

[/ QUOTE ]

This is not controlled by vacuum. It is opened by pressure.

 

[mustangparts65]

Wow... a pump just for the vent operation..

I'll have someone listen to the pump while I turn the key on..

Anything special about replacing the pump? Other than changing over the lines and the wiring?

 

[MOUNTAINMAN444]

[ QUOTE ]
[ QUOTE ]
and the turbo waste gate.

[/ QUOTE ]

This is not controlled by vacuum. It is opened by pressure.

[/ QUOTE ]

I stand corrected.
Joe

 

[mike1963]

I have air conditioner blowing vent problem and fogs up windshield but it puts very little air out dash vents i have a 2007 ford exploere suv someone suggested it might a oring problem